Utilizing mixed amines in gas sweetening process: A Kirkuk field case study and simulation

Abstract

The natural gas sweetening process by using chemical solvents may consider one of the most common and commercial processes that adopted to reduce or remove the hydrogen sulfide and carbon dioxide from the sour gas stream that cause health an environmental risks. An example of this is the North Gas Company's (NGC) sour gas stream, which has concentrations of H2S and CO2 of 2.95% and 2.54%, respectively. A DEA amine system is currently used to reduce these sour component concentrations below 5 ppm and 2% for H2S and CO2, respectfully. This study used Bryan Research and Engineering's ProMax® process simulation software to optimize this amine sweetening system by changing amine types DEA (Diethanolamine) and MDEA(Methyl diethanolamine), amine concentrations, and solvent circulation rates. A 50 wt% MDEA solution circulated at 414 m3/hr was determined to be the optimum operating conditions. This design both met sweet gas specifications and minimized the reboiler duty to 38 MW, a 30.9% reduction in steam consumption.